Method of making a polymeric strip and a power transmission belt

ABSTRACT

A strip of material adapted for use in a power transmission belt construction, method of making such strip, and belt construction and method of making same employing the strip are provided wherein such strip comprises an uncured polymeric matrix material having opposed surfaces and a plurality of elongate reinforcing fibers disposed substantially uniformly throughout the matrix material in a random manner and in parallel relation and a plurality of parallel spaced apart bleeder yarns are adhered against at least one of the surfaces with the strip being adapted to be laminated against associated layer means comprising the belt construction on at least one common interface with the bleeder yarns along the interface and the bleeder yarns are adapted to serve as fluid passages for any fluid present at the interface during curing of the strip and its associated layer means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an uncured fiber-loaded polymeric stripadapted for use in a power transmission belt construction, beltconstruction made using such strip, and method of making such strip andbelt construction.

2. Prior Art Statement

It is known in the art to provide a strip of material adapted for use inmaking a power transmission belt construction wherein the stripcomprises an uncured polymeric matrix material having opposed surfacesand a plurality of elongate reinforcing fibers disposed substantiallyuniformly throughout the matrix material in a random manner and insubstantially parallel relation and as disclosed in U.S. Pat. No.3,464,875.

However, it has been found that with the desired better dispersion ofthe reinforcing fibers throughout the matrix material of the strip,i.e., the fibers are substantially isolated from each other so as topreclude the possibility of such fibers cooperating to define flow pathstherealong, there is a tendency upon attempting to adhere such strip toan adjoining layer means of a belt construction during curing forfluid-containing voids, or the like, to be formed or appear at theinterface of the strip and layer means thereby creating a problem ofpoor bonding at such interface and hence poor lamination of such stripto the layer means. This forming of voids is aggravated where thereinforcing fibers give off fluids during the curing action.

It is also known in the art of making pneumatic tires of polymericmaterial to provide so-called bleeder yarns between adjoining polymericlayers which are free of reinforcing fibers.

It is an object of this invention to provide an improved uncured stripof fiber-loaded polymeric material adapted for use in a powertransmission belt construction.

Another object of this invention is to provide an improved endless powertransmission belt construction made utilizing a strip of the charactermentioned.

Another object of this invention is to provide an improved method ofmaking a strip of the character mentioned.

Another object of this inventon is to provide an improved method ofmaking a power transmission belt construction utilizing such a strip.

Other aspects, embodiments, objects, and advantages of this inventionwill become apparent from the following specification, claims, anddrawings.

SUMMARY

In accordance with the present invention there is provided an improveduncured fiber-loaded polymeric strip for use in a power transmissionbelt construction which overcomes the above-mentioned problem. Theimproved strip is comprised of an uncured polymeric matrix materialhaving opposed surfaces and a plurality of elongate reinforcing fibersdisposed substantially uniformly throughout the matrix material in arandom manner and in parallel relation.

In accordance with one embodiment of this invention parallel spacedapart bleeder yarns are adhered against at least one of the opposedsurfaces and the strip is adapted to be laminated against associatedlayer means comprising a belt construction on at least one commoninterface with the bleeder yarns along the interface, and the bleederyarns are adapted to serve as fluid passages for any fluid present atthe interface during curing of the strip and its associated layer means.

Also provided in accordance with this invention is an improved method ofmaking a strip of the character mentioned.

This invention also provides an improved endless power transmission beltcomprising a tension section, a compression section, and a load-carryingsection with at least one of the sections comprising at least one layerof polymeric matrix material having opposed surfaces and a plurality ofelongate reinforcing fibers disposed substantially uniformly throughoutthe matrix material in a random manner and in parallel relation.Parallel spaced apart bleeder yarns are disposed between at least one ofthe surfaces and adjoining layer means of the belt construction on atleast one common interface with the interface being free of fluid-filledvoids due to the bleeder yarns having served as fluid passages for anyfluid present at the interface during curing of the belt construction.

Also provided in accordance with this invention is an improved method ofmaking a plurality of endless power transmission belts substantiallyidentical to the above-described belt.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings show present preferred embodiments of thisinvention, on which

FIG. 1 is an isometric view with parts in elevation, parts in crosssection, and parts broken away illustrating an exemplary strip ofmaterial of this invention which has bleeder yarns adhered againstopposed surfaces thereof and which is adapted for use in making a powertransmission belt construction, and also illustrating method stepsemployed in making such strip;

FIG. 2 is an isometric view with parts broken away illustrating thestrip of FIG. 1 formed as a layer of extended length and showing suchlayer being wrapped around a toothed belt building drum to define aportion of a belt sleeve;

FIG. 3 is a fragmentary view with parts in cross section and parts inelevation illustrating a small portion of all component layers of anentire belt sleeve wrapped on the building drum of FIG. 2 in preparationfor curing such sleeve;

FIG. 4 is a schematic view illustrating the method steps of curing andcooling the belt sleeve of FIG. 3;

FIG. 5 is a fragmentary view illustrating the cutting of the belt sleeveafter curing and cooling to define a plurality of endless powertransmission belt constructions of this invention;

FIG. 6 is a fragmentary isometric view with parts in cross sectionillustrating a typical belt of this invention;

FIG. 7 is an end view illustrating the strip of this invention formed asa pair of layers and each layer is wrapped in position to define atubular layer of a belt sleeve and with the end portions of each layerbeing disposed in overlapped relation;

FIG. 8 is a fragmentary isometric view illustrating the manner in whichthe bleeder yarns comprising the strip of this invention are disposed inposition in the area of overlapped portions of the outer layer of FIG. 7to provide venting or fluid passages in such area;

FIG. 9 is a view similar to FIG. 1 illustrating another embodiment ofthe strip of this invention and method steps employed in making same;

FIG. 10 is a view similar to FIG. 2 illustrating the strip of FIG. 9formed as layer of extended length and showing such layer being wrappedaround a toothed belt building drum to define a portion of anotherembodiment of a belt sleeve;

FIG. 11 is a view similar to FIG. 6 illustrating another embodiment ofan endless power transmission belt construction of this invention;

FIG. 12 is a view similar to FIG. 10 illustrating a fiber-loaded uncuredlayer means being wound to define a portion of a belt sleeve and whereinbleeder yarns are disposed in position on one surface of the layer meansduring winding thereof;

FIG. 13 is a fragmentary isometric view of one exemplary embodiment of ableeder yarn comprised of a plurality of fluid pervious twisted fibers;and

FIG. 14 is a view similar to FIG. 13 of another exemplary embodiment ofa bleeder yarn comprised of a plurality of twisted monofilaments made offluid impervious material.

DETAILED DESCRIPTION

Reference is now made to FIG. 1 of the drawings which illustrates oneexemplary embodiment of an uncured layer or strip of material which isdesignated generally by the reference numeral 20 and which is adaptedfor use in a power transmission belt construction and as will bedescribed in detail subsequently. The strip 20 may be wrapped or woundto define one or more turns thereof and such turns may then be laminatedin a high strength manner free of fluid-filled voids at the interface ofadjoining turns. Similarly, the strip 20 may be laminated to other layermeans or layers, (e.g., fabric layers, unreinforced polymeric layers,gum cushion layers, etc.) also free of fluid-filled voids at theinterface of such strip with such layer means or layers.

The strip 20 is comprised of a partially or preferably substantiallycompletely uncured (and hence curable) polymeric matrix material whichis designated generally by the reference numeral 21 and which hasopposed surfaces each designated by the same reference numeral 22. Thestrip has a plurality of elongate reinforcing fibers 24 disposedsubstantially uniformly throughout the matrix material in a randommanner and in parallel relation; and, only a representative few of suchfibers are designated by the reference numeral 24. The strip 20 is alsocomprised of a plurality of parallel spaced apart bleeder yarns 25adhered against at least one of the surfaces 22 and in this example ofthe invention the bleeder yarns 25 are adhered against both surfaces 22.The strip 20 is adapted to be laminated against associated layer meanscomprising a belt construction, and as will be subsequently described,on at least one common interface with the bleeder yarns along theinterface. The bleeder yarns 25 are adapted to serve as fluid passagesfor any fluid at the interface during curing of the strip 20 and layermeans associated therewith.

The polymeric matrix material 21 may be any suitable matrix materialemployed in the art of making power transmission belts; and, in thisexample of the invention such polymeric matrix material is a flowablerubber material. The fibers 24 may be made of any suitable materialknown in the art and employed for strengthening or imparting stiffnessto an associated construction and such fibers may have a diameterranging between 0.001 inch and 0.050 inch and a length ranging between0.001 inch and several inches.

Each bleeder yarn 25 is made of at least one fluid pervious member;however, in the embodiment of FIG. 13 of the drawings each bleeder yarn25 is made of a plurality of fluid pervious twisted fibers 26. The fluidpervious twisted fibers 26 may be made of any suitable natural orsynthetic material and twisted cotton fibers have been used successfullyto make yarn 25.

The size of the bleeder yarns 25 used in a particular belt constructionwill vary depending upon the detailed construction thereof. However,each bleeder yarn may have an outside diameter generally of the order ofthousandths and this term is intended to cover the range between 2through 20 thousandths. Generally the bleeder yarns of a given strip 20and belt construction will be of the same size and it is to beunderstood that such yarns are used solely to provide a bleeding orventing function inasmuch as they are not usually constructed to providea strengthening function.

The bleeder yarns 25 need not necessarily be made of fibers or membersconsisting of fluid pervious material. Indeed each yarn 25 may be madeof fluid impervious material whereby FIG. 14 illustrates an exemplaryyarn 25 made of a plurality of twisted fluid impervious monofilaments27. The twisted monofilaments 27 have spaces 30 therebetween whichcooperate to define fluid passage means or venting means along each yarn25.

As described earlier, the strip 20 has parallel bleeder yarns 25 adheredagainst both of its opposed surfaces 22 and such yarns are disposedsubstantially transverse the elongated fibers 24. This reference todisposal of the yarns transverse the fibers is intended to define thatthe yarns 25 are disposed transverse the longitudinal axes of theparallel fibers 24. In the example of the strip shown in FIG. 1, theparallel yarns 25 on each surface 22 are disposed at an angle 31 ofapproximately 45° to the reinforcing fibers 24. This disposal of thebleeder yarns 25 at 45° enables the utilization of the strip 20 or anassociated layer defined from such strip in applications where it isnecessary to join overlapped end portions of such strip or layer andstill provide bleeder passages or venting in the area of the overlappedportions and as will be described in more detail subsequently.

The strip 20 may be made employing the basic method 33 illustrated inFIG. 1 and such method comprises the steps of providing a mass ofuncured yet readily formable polymeric matrix material 21 and mixing aplurality of the elongate reinforcing fibers 24 throughout the matrixmaterial using any suitable mixing apparatus (not shown) known in theart to define a fiber-loaded mass as illustrated at 35 in FIG. 1. Themass at 35 is then formed, using any suitable forming means known in theart, to define the strip 20 which has opposed surfaces 22.

The process of making the strip 20 comprises aligning the fibers 24randomly yet substantially uniformly throughout the matrix material 21with the elongate axes in parallel relation and as shown at 36. Theforming and aligning steps are achieved in a simultaneous manner bycalendering the mass at 35 between calendering rolls 37, which may be ofany suitable type known in the art.

The method 33 also includes the step of adhering a plurality of bleederyarns 25 against at least one of the opposed surfaces 22 and in thisexample the method comprises adhering bleeder yarns 25 against both ofthe surfaces 22 and this is achieved utilizing the apparatus 40. Theapparatus 40 may be of any type capable of adhering bleeder yarns 25against the opposed surfaces 22; and, it will be appreciated that suchapparatus will utilize spools for the bleeder yarns and associatedmechanisms for disposing such bleeder yarns with the desired spacingtherebetween and in parallel relation on each surface.

In this example of the invention the strip 20 has its elongate fibers 24extending parallel to the flow or strip forming direction; and, such astrip may be made of basically unlimited length. There are manyapplications where the strip 20 may be wound about an axis of a beltbuilding drum where the fibers 24 are perpendicular to such axis, and inthese applications the strip 20 may be used essentially as defined inFIG. 1. However, in applications, as the present one, where the strip 20is wound with its fibers 24 parallel to the longitudinal axis of a beltbuilding drum 43, as shown in FIG. 2, it may be necessary to cutrectangular equal width portions of the strip perpendicular the flowdirection 42 and adhere these cut portions in end-to-end relation. Thiscutting and adhering is well known in the art and thus will not bedescribed herein. The resulting strip will be referred tointerchangeably in this specification as a strip or layer and will alsobe designated by the reference numeral 20 throughout the drawings. Itwill be appreciated that depending on the width 41 and the size of aparticular endless belt to be made using the strip 20 a singlerectangular portion may be cut from the strip of FIG. 1, rotated 90degrees and simply wound on its drum 43 to define one or more layers ofa belt sleeve.

The strip or layer 20 may be used in making a plurality of endless powertransmission belt constructions and as will now be described inconnection with FIGS. 2, 3, 4, and 5 of the drawings. In particular, themethod comprises the steps of forming an uncured belt sleeve which isdesignated generally by the reference numeral 44 in FIG. 3 of thedrawings. The belt sleeve 44 has a tension section defining portion 45,a compression section defining portion 46, and a load-carrying sectiondefining portion 47. The forming of the belt sleeve 44 compriseswrapping, so as to comprise at least one of the above-described portions45 through 47, a layer 20. The forming of the belt sleeve is achievedaround the previously mentioned conventional belt building drum 43(FIGS. 2 and 3) which has teeth 48 defining its outside surface.

The belt sleeve is then cured in a curing apparatus 50 and cooled in acooling apparatus 51 as shown schematically in FIG. 4. The curingapparatus 50 and cooling apparatus 51 may be of any suitable type knownin the art.

The cured and cooled belt sleeve 44 is then removed from its buildingdrum 43 and disposed on a cutting mandrel 52, as illustrated in FIG. 5.The belt sleeve 44 is cut using mechanical cutting devices or knives 53and each knife 53 is moved into and out of cutting engagement employingan associated actuating mechanism 54 which is designated schematicallyby a double arrow.

Except for the utilization of the strip or layer 20 to define the beltsleeve 44 the build up thereof on building drum 43 is well known andwill only be described briefly. It is desired, in this example, to makethe belt sleeve 44 (and belts to be made therefrom) with a fabric insidelayer 56 as well as a fabric outside layer 57. The inside layer 56 ispreferably disposed in snug relation against the undulating outsidesurface of the toothed building drum 43 utilizing techniques which areknown in the art.

Once the fabric layer 56 is in position on the drum 43 the strip orlayer 20 is wrapped in position, as shown in FIG. 3, and in this examplefour turns of the layer 20 are wrapped in position and cooperate withthe fabric layer to define portion 46 of the belt sleeve 44.

The lower cushion, gum cushion 60, of the load-carrying section definingportion 47 is then wound in position, followed by helically winding theload-carrying cord 61, and then followed by winding the top cushion 62outwardly of the load-carrying cord 61.

Another length of the strip or layer 20 is then wrapped in positionoutwardly of the top cushion 62 to define two turns thereof followed bythe outside fabric layer 57. The outside fabric layer 57 and twoadjoining turns of layer 20 define the tension section defining portion45 of the sleeve 44.

The strip or layer 20 has bleeder yarns 25 on both of its surfaces 22.Thus, it is apparent that bleeder yarns 25 are disposed throughout theuncured belt sleeve 44 and when viewed in cross section or toward theend thereof such yarns are illustrated as enlarged dots with only a fewof such dots being designated by the reference numeral 25.

Accordingly, it will be seen that bleeder yarns 25 are disposed at theinterface of the inner fabric layer 56 and the inner turn of the strip20, at the interface of adjoining turns of the strip 20 in the sleeveportion 46, and at the interface of the outermost turn of the strip 20and the lower cushion 60. It will also be seen that bleeder yarns 25 aredisposed at the interface of the top cushion 62 and the inner turn ofthe strip 20 in sleeve portion 45, at the interface of adjoining turnsof the strip 20 in sleeve portion 45, and at the interface of the outerturn of the strip 20 and the outer fabric layer 57.

In accordance with the teachings of this invention the bleeder yarns 25serve as fluid passages for conveying any fluid present at eachinterface away therefrom during the curing of the sleeve 44 in thecuring device 50. This results in each interface being free offluid-filled voids and thereby results in each corresponding interfaceof an associated power transmission belt construction, made from thecured sleeve 44, also being free of fluid-filled voids.

Once the belt sleeve 44 is cured and cooled (FIG. 4), as describedearlier, it is cut (FIG. 5) to define a plurality of belts and each ofsuch belts is designated by the reference numeral 64. A typical belt 64is shown in FIG. 6.

The belt 64 has a tension section, a compression section, andload-carrying section which, for simplicity, are designated by the samerespective reference numerals 45, 46, and 47 as corresponding beltdefining portions of the uncured belt sleeve 44. Further, it will beseen that at least one of the sections is comprised of at least oneintegral layer or turn of the strip 20. Inasmuch as the belt 64 is madefrom the belt sleeve 44 the tension section 45 thereof is comprised oftwo turns of the strip 20 and the compression section 46 is comprised offour turns of strip 20.

As described in connection with the method of making the belt sleeve 44,the completed belt 64 has a plurality of parallel spaced apart bleederyarns 25 disposed at the previously described interfaces. However, itwill be appreciated that such interfaces are not present and hence notvisible, as such, in the completed belt 64 due to the polymeric materialhaving moved and adhered in position during curing so that the belt 64is a single void free structure. Nevertheless, the bleeder yarns 25 ateach interface have served as fluid passages for any fluid present atthe interface during curing of the belt construction and morespecifically, in this example, during curing of the belt sleeve fromwhich the belt 64 has been cut.

In the above description a length of the strip 20 has been described asbeing wrapped or wound in a plurality of two adjoining turns in beltsleeve portion 45 and another length of the strip 20 has been wrapped ina plurality of four adjoining turns in belt sleeve portion 46. However,the strip 20 lends itself to making portions of a belt sleeve, and hencea belt 64, in which a single turn of the strip 20 may be wrapped intoposition with opposite end portions overlapped to define a part of aparticular belt sleeve portion and without concern for venting of theoverlapped end portions which is usually a problem with this latter typeof construction.

For example, in the illustration of FIG. 7 a length of strip 20 is usedto define an inner layer 66 of a compression section defining portion 46of a belt sleeve 44. The layer 66 has an inner end portion 67 disposedagainst the toothed building drum 43 whereupon the layer 66 is thenwrapped around the complete circumference of the building drum and hasan end portion 68 overlapped against the inner portion 67. Anotherlength of strip 20 may be used to define the next layer 70 which adjoinsthe layer 66. The layer 70 has an inner end portion 71 disposed againstlayer 66 at a location which is substantially diametrically oppositeportions 67-68 and layer 70 has a terminal end portion 72 overlappedagainst end portion 71. Any desired number of lengths of strip 20 may beused to define a corresponding number of layers and preferably theoverlapped end portions are circumferentially staggered. However, theunique character of the strip 20 results in venting being provided atthe overlapped end portions of each layer.

FIG. 8 of the drawings is typical of the venting action provided and isshown for the end portions 71 and 72 of layer 70; and, it is seen thatbleeder yarns 25 extend from the area of the overlapped portions 71-72to the ends of the layer 70 overlying the ends of the drum 43. The nearend of the drum 43 is shown in FIG. 8 together with the near end of thelayer 70 and exposed ends of bleeder yarns 25.

In the illustrations of FIGS. 7 and 8, the overlapped end portions oflayers 66 and 70 appear to provide a substantial increase in radialthickness to each layer at the overlapped locations. However, thisincreased thickness is not only exaggerated for clarity but alsoessentially disappears once the belt sleeve is cured due to shifting ofthe polymeric material during curing. Accordingly, the resulting beltsleeve is basically free of bulges, or the like, yet bleeder yarns haveperformed their intended function. It will also be appreciated that withthe bleeder yarns 25 disposed substantially at 45° the desired bleedingor venting in the area of joints is also achieved when joining ends ofstrip 20 using butt joints, bevel-type joints, and the like.

The strip 20 need not necessarily be made with bleeder yarns on bothsurfaces 22 thereof and at an angle of 45° with the fibers 24. Forexample, a modification of the strip 20 is provided in FIG. 9 in which aplurality of bleeder yarns 25 are adhered against only one surface andparallel to such fibers 24.

The strip 20 of FIG. 9 is made by forming a flowable mass of polymericrubber material 21 having reinforcing fibers 24 dispersed therethroughusing calendering rolls 37. Simultaneously with this forming actionparallel spaced apart yarns 25 are adhered against the bottom surface22, as viewed in FIG. 9, of the strip 20. This adhering action isachieved by passing each yarn between the top of the lower calenderingroll 37 and the bottom surface 22 of the strip 20. The yarns 25 may befed between the lower calendering roll 37 and the bottom surface 22while simultaneously unwinding same from associated rotatable spools(not shown) and as is known in the art.

The strip 20 of FIG. 9 may be disposed or processed as previouslydescribed so that the fibers 24 and yarns 25 thereof are disposedparallel to the longitudinal axis of the belt building drum 43 and asillustrated at 75 in FIG. 10.

It will also be appreciated that instead of adhering the yarns 25against a surface of a strip of uncured polymeric matrix material duringthe initial forming of such strip it may be preferred to adhere thebleeder yarns 25 and complete the strip immediately prior to using sameand as illustrated in FIG. 12. In particular, a strip or layer ofuncured polymeric matrix material may be provided which has the fibers24 embedded therein with the desired orientation and as illustrated at76. Immediately prior to wrapping or winding the strip on a beltbuilding drum 43 a plurality of parallel spaced apart bleeder yarns 25are suitably disposed against the strip to define the completed strip20. The bleeder yarns 25 in this instance may be disposed in positionutilizing any suitable technique known in the art and such bleeder yarnsmay be disposed in position manually, if desired.

The strip 20 shown in either FIG. 10 or FIG. 12 may be suitably wrappedor wound in position against an associated building drum 43 asillustrated in each of these FIGS. and may be used to define a pluralityof inner turns of a compression section defining portion of a beltsleeve. Further, the number of turns used will vary depending on thedesired construction of the endless power transmission belt to bedefined from such sleeve. It will also be noted that in theillustrations of FIGS. 10 and 12 each strip 20 is wrapped in positionagainst the teeth 48 of the belt building drum 43 without wrapping offabric material snugly against the teeth whereby the resulting beltsleeve and endless power transmission belts defined therefrom will befree of an inside fabric layer. The remainder of the belt sleeve isdefined in a similar manner as the belt sleeve illustrated in FIG. 3 andthe belt sleeve thus defined is suitably cured, cooled, and cut in asimilar manner as described previously to define a plurality of endlesspower transmission belts.

A typical belt made from a belt sleeve which uses either the strip ofFIG. 10 or the strip of FIG. 12 is illustrated in FIG. 11 of thedrawings and such belt is similar to the belt 64 previously describedwhereby such belt will be also designated by the reference numeral 64followed by the reference letter A. The belt 64A also has sections whichcorrespond to sections of the belt 64 and these sections of belt 64Awill be designated by the same reference numerals as previously alsofollowed by the letter designation A and not described in detail.

Accordingly, the belt 64A comprises a tension section 45A, a compressionsection 46A, and a load-carrying section 47A. The belt 64A utilizes aplurality of turns of a strip of polymeric material which has not beenreinforced to define tension section 45A and such tension section has anoutside fabric layer 57A. The belt 64A also has a load-carrying section47A which is substantially identical to the load-carrying section 47previously described.

There are three main differences between the belt 64A and the belt 64.The first difference is that the belt 64A has its compression section46A made free of an inside fabric layer. The second difference is thatthe bleeder yarns 25 between the interfaces of adjoining turns of thestrip 20A used to define the compression section are disposed parallelto the reinforcing fibers and both such fibers and bleeder yarns aredisposed perpendicular to the longitudinal axis of the belt. The thirddifference is that the tension section 45A is made of rubber free of orwithout reinforcing fibers 24, or the like.

In this disclosure of the invention each belt 64 and 64A is shown ashaving a toothed compression section; however, it is to be understoodthat the teachings of this invention may be utilized in defining alltypes of belts including plain V-belts which are free of teeth in theircompression section, timing or synchronous belts, belts with teeth inboth the tension and compression sections, ribbed belts of all types,flat belts, banded belts, or any other type of endless powertransmission belt known in the art.

While present exemplary embodiments of this invention, and methods ofpracticing the same, have been illustrated and described, it will berecognized that this invention may be otherwise variously embodied andpracticed within the scope of the following claims.

What is claimed is:
 1. In a method of making a substantially rectangularstrip of material having opposed ends and being adapted for use in apower transmission belt construction, said method comprising the stepsof providing a mass of uncured formable polymeric matrix material,mixing a plurality of elongate reinforcing fibers throughout said matrixmaterial, forming said mass to define a strip thereof having opposedsurfaces, each surface having a pair of opposed side edges and a pair ofopposed end edges, aligning said fibers randomly and substantiallyuniformly throughout said matrix material with their elongate axes inparallel relation, the improvement comprising the steps of adhering aplurality of parallel spaced apart bleeder yarns against at least one ofsaid surfaces so that each edge of said one surface has a plurality ofsaid bleeder yarns extending thereto, said bleeder yarns enabling saidstrip to be laminated against associated layer means comprising saidbelt construction on a common interface with said bleeder yarns alongsaid interface as well as enabling said strip to have said opposed endsdisposed in overlapping relation on a common interface therebetween withcertain of said bleeder yarns along said interface of said ends, saidbleeder yarns being adapted to serve as fluid passages for any fluidpresent at said interfaces during curing of said strip and itsassociated layer means.
 2. A method as set forth in claim 1 in whichsaid forming and aligning steps are achieved in a simultaneous manner bycalendering said mass with said fibers therein between calenderingrolls.
 3. A method as set forth in claim 2 and comprising the furtherstep of defining each of said bleeder yarns by twisting a plurality offluid pervious fibers.
 4. A method as set forth in claim 2 andcomprising the further step of defining each of said bleeder yarns bytwisting a plurality of monofilaments each made of fluid imperviousmaterial, said twisted monofilaments defining fluid passage meanstherebetween.
 5. A method as set forth in claim 2 in which said step ofadhering said yarns comprises adhering said yarns at an angle ofapproximately 45° to said reinforcing fibers and to said edges.
 6. Amethod as set forth in claim 2 in which said step of adhering said yarnscomprises adhering a second plurality of parallel spaced apart yarnsagainst the other of said surfaces, said strip being adapted to belaminated against said associated layer means having said first-namedplurality of bleeder yarns on said one common interface and having saidsecond plurality of bleeder yarns on a second common interface with saidlayer means, said second plurality of bleeder yarns serving as fluidpassages for any fluid present at said second common interface duringcuring of said strip and layer means.
 7. In a method of making aplurality of endless power transmission belt constructions comprisingthe steps of; forming a belt sleeve having a tension section definingportion, a compression section defining portion, and a load-carryingsection defining portion; said forming step comprising the step ofwrapping a substantially rectangular layer of polymeric matrix materialhaving opposed surfaces and a plurality of elongate reinforcing fibersdisposed substantially uniformly throughout said matrix material in arandom manner and in parallel relation to form one of said portions,each surface having a pair of opposed side edges and a pair of opposedend edges; curing said belt sleeve; and cutting said belt sleeve todefine said plurality of belt constructions; the improvement comprisingthe steps of, disposing a plurality of parallel spaced apart bleederyarns between at least one of said surfaces and adjoining layer means ofsaid belt sleeve on at least one common interface so that each edge ofsaid one surface has a plurality of said bleeder yarns extendingthereto, said bleeder yarns serving as fluid passages for conveying anyfluid present at said interface away therefrom during said curing stepresulting in said interface being free of fluid-filled voids and therebyresulting in the corresponding interface of an associated powertransmission belt construction cut from said belt sleeve during saidcutting step also being free of fluid-filled voids.
 8. A method as setforth in claim 7 in which said forming step comprises wrapping saidlayer to comprise said compression section defining portion.
 9. A methodas set forth in claim 7 in which said forming step comprises wrappingsaid layer to comprise said tension section defining portion.
 10. Amethod as set forth in claim 7 in which said forming step compriseswrapping said layer with opposite end portions in adjoining relation,said bleeder yarns of said layer at said end edges also serving as fluidpassages for conveying any fluid present at said adjoining end portionsaway therefrom during said curing step.
 11. A method as set forth inclaim 7 in which said forming step comprises wrapping said layer withopposite end portions in overlapped relation, said bleeder yarns at saidend edges also serving as fluid passages for conveying any fluid presentat said overlapped end portions away therefrom during said curing step.12. A method as set forth in claim 7 in which said forming stepcomprises wrapping said layer in a plurality of turns.